The design of a timepiece movement generally endeavours to create a common platform, on the basis of which it is possible to offer a variety of different, multi-option variants. The objective is therefore to ensure that the components of the basic movement do not interfere with those of any of the proposed variants, so that the movement can be used as it is, without disassembling or exchanging any components, and personalisation options are achieved simply by adding additional components. In particular, for the positioning of seconds displays, notably centre seconds or off-centre small seconds, the objective is to avoid being able to mount different arbors for each option, while also ensuring that the unused arbors do not create any interference with the dial, or the hands or the crystal.
Conventionally, centre displays include concentric, stepped cannon-pinions and arbors, all protruding above the surface of the dial, and the same holds true for small seconds arbors, which project above the level of the dial. Versatile usage therefore entails a dial having as many orifices as there are options for positioning small seconds arbors, or other current time display functions, or timing functions, or other functions, which detracts from the attractiveness of the timepiece.
DE Patent Application No 19641894A1 in the name of Hillgruber describes the fitting of hands to a cannon-pinion or arbor via a helical spring, said spring being contained in an external guide tube.
EP Patent Application No 0862098A2 in the name of Voss describes a modular watch with annular fittings for the hands.
U.S. Pat. No. 4,378,957A in the name of Malkin describes a seconds arbor pivoting in a bearing of the cannon-pinion, the axial stops of the other cannon-pinions being formed by their drive wheels.
DE Patent Application No 4032879A1 in the name of Yazaki Corp describes the relative axial cooperation of tubes and cannon-pinions via annular grooves and flanges.